1. Field of the Invention
This invention relates to novel superconductors, and more particularly to solid compositions which are oxides of barium, lead and bismuth.
2. Background of the Invention
Superconducting oxide compounds are rare. In most structures the presence of oxygen is detrimental to superconductivity. The only oxide with a superconducting state above 7K is reported to be a spinel structure having a composition near LiTi.sub.2 O.sub.4 (Johnston et al., Mat. Res. Bull. 8, p. 777-784 (1973)).
The compound BaPbO.sub.3 is described by Shannon and Bierstedt in Jour. Am. Ceram. Soc., vol. 53, p. 635-636 (1970). Metallic conduction is shown with a room temperature resistivity of about 300 micro ohm cm. which extrapolates to about 90 .times. 10.sup..sup.-6 ohm cm. at OK. A diffraction pattern is given which is interpreted as a perovskite structure with orthorhombic distortion.
The compound BaBiO.sub.3 is described by Scholder et al., Z. anorg. allgem. Chemie, 319, 375-386 (1963) as having an ordered perovskite structure. No properties are given.